Pressure injector



Dec. 28, 1965 w. o. ALEXANDER 3,225,554

PRESSURE INJECTOR Filed Nov. 5, 1964 2 Sheets-Sheet l INVENTOR.

WILLIAM o. ALEXANDER ATTORNEY 1965 w. o. ALEXANDER 3,225,554

PRESSURE INJECTOR Filed Nov. 5, 1964 2 ts-Sh 2 INVENTOR.

WILLIAM O. ALEXANDER ATTORNEY United States Patent 4 Claims. or. 6277) This application is a substitute application of abandoned application No. 297,879 for Pressure Injector, filed July 26, 1963.

This invention relates to an apparatus for injecting lubricants into a refrigeration apparatus. More specifically, this invention relates to a method and means whereby oil may be charged to the motor compressor in a refrigeration system without contamination of the system. More specifically, this invention relates to a method whereby oil may be removed from a motor compressor and thereafter charged with the correct quantity of lubricant.

Before a refrigeration system is charged with lubricant or refrigerant gas, it is necessary to remove all noncondensable gases, such as air, from the system. The presence of non-condensable gases tends to cause excessive head pressures in the pressure side of the system so that the efliciency of the system will be impaired and, if the amount of non-condensable gases are sufficiently large, the machine may even cease to function. Furthermore, oxygen may cause oxidation or deterioration of certain parts of the refrigeration apparatus. In addition, the oxygen tends to react with the lubricants and refrigerants to form water and other chemical compounds which may cause deterioration, oxidation and rusting of various parts.

It is an object of my invention to provide a pressure injector whereby oil may be charged to a motor compressor while the motor is either in or out of operation and without contamination of the system with air or other non-condensables.

It is a further object of my invention to provide a method and means whereby oil may be added to the motor compressor with the use of a pressurized refrigerant.

It is a further object of my invention to provide a method whereby oil and sludge may be removed from the motor compressor quickly and economically and be replaced with new oil.

Other objects will occur to those skilled in the art by reference to the attached drawings and the following detailed description.

Referring now to the drawings, FIG. 1 is a diagrammatic view of my invention as applied to a conventional refrigeration apparatus.

FIG. 2 is a sectional view of my pressure oil injector illustrating the various fittings.

FIG. 3 is a diagrammatic view of a portion of a refrigeration system illustrating a means for removing oil from the motor compressor without contaminating same.

FIG. 4 is a sectional view of a fragment of the pipe and tube assembly taken along lines 4-4 of FIG. 3.

FIG. 5 is an enlarged sectional view of the pressure regulating fitting taken along line 5-5 of FIG. 1.

In the drawings motor compressor 1 contains an oil eservoir 2 which communicates with the outside atmosphere through a channel in oil boss 3. The pressure valve 4 on the pressure side of the compressor connects by means of fitting 5 to pressure conduit 6 which conveys pressurized refrigerant to condenser 7. Condenser 7, containing a fan (not shown), to condense the pressurized refrigerant, communicates with liquid refrigerant reservoir 8 which is, in turn, connected to liquid conduit 9 Patented Dec. 28, 1965 to convey the liquid refrigerant to expanding coil 11.

The liquid refrigerant passes through chamber 10 containing a dessicant to remove any traces of moisture. The expanded gases are returned to the suction side of the compressor via conduit 12 connected by fitting 13 to suction valve 14 to complete the cycle. Pressure and suction valves 4 and 14 are of the type disclosed by Weatherhead in U.S. 1,924,007.

The prior practice, if it became necessary to charge oil to the motor compressor while in operation, was to front seat the suction valve 14 causing a vacuum to be drawn on the oil reservoir and then insert a tube in a can of oil and draw in the oil through the suction valve. This procedure not only contaminated the oil but was messy and time consuming. Further, it was impossible to accurately measure the amount of oil added.

By use of my oil pressure injector, oil may be added to the motor compressor in a matter of a few minutes. This apparatus consists of an oil container 15, oil 16, oil stem 17 and exhaust and pressure regulator fitting 18. A refrigerant opening 34 connects to conduit 28 by coupling 19 which leads to refrigerant tank 50. The top 40 of the oil container contains also a liquid discharge fitting 3t) which connects with conduit 20 by coupling 45 to convey oil to fluid manifold 21. Fluid manifold 21 contains pressure gauges 22 and 23 which are connected to suction valve 14 and pressure valve 4, respectively, by means of conduits 27 and 26. Additionally, manifold 21 contains manually controlled valves 24 and 25.

Referring now to FIGS. 2 and 5, it will be seen that the exhaust and pressure regulating fitting 18 consists of a threaded pipe 39 which extends through top 40 of the oil container. The boss member is held in position by nut 37 and contains a flare nut and dome 36 which has a hole 35 in its side wall. Thus, when the flare nut and dome 36 is screwed down tight, the hole 35 does not communicate with the interior of the oil containers, however, in the extended position the hole 35 extends through the channel of boss 39 to communicate with the oil container and the outside atmosphere.

The liquid discharge fitting 30 consists of a threaded elbow 33 which is held in position by nut 31 and contains hose coupling 45 at its outer end. Refrigerant opening 34 consists of a threaded pipe 32 held in positon by nut 38 for attachment to hose coupling 19 of conduit 28. Conduit 28 is attached to tank 50 by means of coupling 29.

Operation The operation of this apparatus consists first of adding oil 16 to the container. The top 44) is then attached to the container and is sealed by means of oil resistant gasket 46. Various lines are connected and the flare nut and dome is unscrewed so that the hole 35 communicates with oil container. Thereafter, valve 41 of tank 50 is opened so as to admit pressurized refrigerant such as Freon to the container to exhaust all the air therefrom. The entire manifold and other conduits may also be similarly exhausted of air. Thereafter, the conduit 26 is connected to pressure valve 4 and conduit 27 is connected to suction valve 14. It is not essential to connect line 26 to pressure valve 4, since oil is injected through suction valve 14. However, in some instances it may be desirable to measure the head pressure and regulate same. By addition of additional refrigerant and by manipulation of the flare nut and dome apparatus the flow of oil can be regulated to the suction side of the apparatus. In this manner, the oil is pumped or injected into the motor compressor without any contamination from the outside atmosphere. Should the additional oil and refrigerant raise the head pressure as reflected on gauge 23 beyond reasonable limits, hand valve 41 may be closed and hand valve 25 and pressure and regulating member 18 may be opened in order to vent additional refrigeration to the atmosphere and thus regulate the head pressure of the compressor.

Oil removal In some instances, it is desirable to remove old oil containing sludge, water and other contaminants from the motor compressor reservoir. In such an instance, the pressurized refrigerant tank 50 is connected via conduit 28 directly to the manifold 21. (See FIG. 3.) The plug is removed from the oil boss 3 and a tube 51 contained in threaded pipe member 54 adapted to engage with the threads of the oil boss is placed therein. The pipe member is threaded at its outer end to engage with a cap and is sealed by means of an ring seal 53 to prevent leakage around tube 51. Tube 51 is inserted into the oil reservoir until it reaches the bottom of motor compressor 1. The pressure is released from the pressure side of the compressor by opening valve 4 and then valve 41 of the Freon tank 50 is opened. The pressurized refrigerant passing via conduit 28 through manifold 21 and conduit 27 forces the oil from the reservoir out through the tube 51 and into a suitable receptacle 55. After the oil is out, I have found it desirable to clean the compressor with a cleaning compound such as Freon 11. Other materials, such as carbon tetrachloride, may be utilized, however, due to the hazards of inhalation of such materials Freon 11 is preferred. Freon 11 is a cleaning refrigerant and is in liquid form at 70 F., therefore, with the tube 51 still in position, as shown in FIG. 3, a tank of Freon 11 is connected to line 28 by coupling 29. Valve 41 on the tank 59 is open. Thereafter, the fluid oil injector 15 is connected into the line as illustrated in FIG. 1 and a small amount of oil is added. The tank of Freon 11 is then replaced by a tank of conventional refrigerant Freon 12 and valve 41 is opened to remove the oil containing the Freon 11 from the compressor The compressor is then cleaned. Thereafter, additional oil is added to the container 15 which is flushed out with Freon 12 as previously indicated. The tube and pipe assembly 51 through 54 are removed and the oil plug is secured in oil boss 3. Thereafter, the proper amount of oil is added to the compressor in the manner previously set forth.

In some instances, it may be necessary to flush out the initial charge of oil and add another charge and, in the event that moisture is the chief contaminant, to Warm the compressor up to evacuate the moisture prior to adding the final charge of lubricant.

It will be appreciated that many modifications can be made in the apparatus herein disclosed and the specific embodiments which are illustrative in nature. Therefore, I desire that my invention be construed to be nonlimiting except as to be commensurate in scope with the appended claims.

I claim:

1. For use with a motor compressor in a refrigeration system which contains (a) a suction valve on the suction side of the compressor;

(b) a pressure valve on the pressure side of the compressor;

(0) an oil reservoir and an exterior oil boss containing a channel which communicates with said oil reservoir,

a portable service pressure injector wherein oil may be added to the motor compressor without contaminating the refrigerant therein which comprises:

(a) an oil container and a source of pressurized refrigerant in which (i) said oil container contains a refrigerant fitting for connection to a pressurized refrigerant source, a manually operated exhaust and pressure regulating valve, operative to exhaust the container of non-condensible gases and thereafter to regulate the pressure in the container, therefore regulating the rate of the oil flow, a liquid discharge fitting including an oil stem which extends downwardly so as to terminate in proximity to the bottom of said container and a means for placing a pre-determined amount of oil into said container, in combination with (b) connecting means for connecting said pressurized refrigerant source to said refrigerant fitting and for connecting said liquid discharge fitting to said suction valve on said motor compressor whereby said oil container may first be exhausted of non-condensable gases and thereafter used to inject oil under pressure into said motor compressor.

2. A method for removing and replacing oil in a motor compressor which contains:

(a) a suction valve on the suction side of the motor compressor;

(b) a pressure valve on the pressure side of the motor compressor;

(c) an oil reservoir and an exterior oil boss containing a channel which communicates with said oil reservoir,

the improvement of removing and replacing oil without contaminating the system which comprises the steps of:

(i) connecting a pressurized refrigerant to said suction valve;

(ii) inserting a tube into said channel of said oil boss and sealing same from the atmosphere;

(iii) injecting refrigerant through said suction valve to force said oil through said tube out of the motor compressor;

(iv) removing said tube and sealing means from said oil boss and sealing same;

(v) connecting said pressurized refrigerant to a container containing new oil and connecting said container to said suction valve;

(vi) displacing non-condensable gases in said container with pressurized refrigerant;

(vii) injecting new oil into said compressor through said suction valve using pressurized refrigerant as a propellant; and

(viii) controlling the pressure in said container and therefore controlling the flow of oil from said container and into said compressor by venting excess pressurized refrigerant from said container while injecting said oil into said compressor.

3. A method of removing and replacing oil in a motor compressor and cleaning said motor compressor in which said motor compressor contains:

(a) a suction valve on the suction side of the compressor;

(b) a pressure valve on the pressure side of the compressor;

(c) an oil reservoir and an exterior oil boss containing a channel which communicates with said oil reservoir which comprises the steps of:

(i) connecting a pressurized refrigerant to said suction valve;

(ii) inserting a tube into said channel of said oil boss and sealing same from the atmosphere;

(iii) injecting refrigerant through said suction valve to force said oil through said tube out of the compressor;

(iv) disengaging said pressurized refrigerant from said suction valve;

(v) connecting a pressurized cleaning refrigerant to said suction valve and injecting same into said motor compressor;

(vi) disconnecting said pressurized Cleaning refrigerant from said suction valve;

(vii) connecting said pressurized refrigerant to a container containing new oil and connecting said container to said suction valve;

(viii) displacing non-condensable gases from said oil container with pressurized refrigerant;

(ix) injecting new oil into said compressor;

(x) connecting said pressurized refrigerant to said suction valve and injecting same to force the cleaning refrigerant and oil from said compressor;

(xi) removing said tube and sealing means from said oil boss and sealing same;

(xii) connecting said pressurized refrigerant to a container containing new oil and connecting said container to said suction valve;

(xiii) displacing non-condensable gases from said container with pressurized refrigerant; and

(xiv) injecting new oil into said compressor through said suction valve.

4. A method of injecting oil into a motor compressor without contaminating same in which said motor compressor contains (a) a suction valve on the suction side of the compressor;

(b) a pressure valve on the pressure side of the compressor;

(c) an oil reservoir and an exterior oil boss containing a channel which communicates with said oil reservoir which comprises the steps of:

(i) connecting a pressurized refrigerant to a container containing oil;

(ii) displacing non-condensable gases from said container by injecting pressurized refrigerant therein;

(iii) connecting said container onto the suction valve of said motor compressor;

(iv) injecting pressurized refrigerant into said container to inject non-contaminated oil into said motor compressor; and

(v) controlling the pressure in said container so as to control the flow of oil from said container and into said motor compressor by venting excess pressurized refrigerant from said container While injecting said oil into said motor compressor.

References Cited by the Examiner UNITED STATES PATENTS 1,839,197 1/1932 Carney 62292 X 2,462,535 2/1949 Murphy 62292 2,499,170 2/1950 Shoemaker 62292 X 3,118,463 1/1964 Lacart 6277 X OTHER REFERENCES Publication: Modern Refrigeration and Air Conditioning, Althouse et a1., published by Goodheart-Willcox Company Inc., Chicago (1956) (pages 271 and 286, relied on).

ROBERT A. OLEARY, Primary Examiner.

LLOYD L. KING, Examiner. 

1. FOR USE WITH A MOTOR COMPRESSOR IN A REFRIGERATION SYSTEM WHICH CONTAINS (A) A SUCTION VALVE ON THE SUCTION SIDE OF THE COMPRESSOR; (B) A PRESSURE VALVE ON THE PRESSURE SIDE OF THE COMPRESSOR; (C) AN OIL RESERVOIR AND AN EXTERIOR OIL BOSS CONTAINING A CHANNEL WHICH COMMUNICATES WITH SAID OIL RESERVOIR, A PORTABLE SERVICE PRESSURE INJECTOR WHERIN OIL MAY BE ADDED TO THE MOTOR COMPRESSOR WITHOUT CONTAMINATING THE REFRIGERANT THEREIN WHICH COMPRISES: (A) AN OIL CONTAINER AND A SOURCE OF PRESSURIZED REFRIGERANT IN WHICH (I) SAID OIL CONTAINER CONTAINS A REFRIGERANT FITTING FOR CONNECTION TO A PRESSURIZED REFRIGERANT SOURCE, A MANUALLY OPERATED EXHAUST AND PRESSURE REGULATING VALVE, OPERATIVE TO EXHAUST THE CONTAINER OF NON-CONDENS- 